The invention is in the field of piece-good processing and concerns a method according to the generic part of the first independent claim as well as a controlling method and an installation according to the generic parts of the corresponding independent claims and serving for controlling and for carrying out the inventive method. With the aid of the inventive method, piece-goods are processed whereby the term `piece-goods` herein is to be understood as items in large numbers being processed mainly individually, being handled in an organized configuration (as opposed to bulk goods) and having same or at least partly similar characteristics (e.g. different printed products and parts of printed products) such that items to be handled and processed in succession can be handled and processed with substantially the same means and in substantially the same manner.
The term `method for processing piece-goods` herein is to be understood as a method:
to which items (starting products) are supplied in the form of at least one product stream (e.g. printed products or product parts from a rotary printing machine or from stock), PA1 in which in at least one processing step starting products and/or intermediate products are processed, whereby the processing step (e.g. trimming, stitching, binding, addressing, folding) changes at least one characteristic of a processed item and/or whereby in the processing step products are joined (by e.g. gathering, inserting, collating, or stacking product parts) to form new items with new characteristics and PA1 from which items are conveyed away as end products again in at least one product stream.
The items to be supplied to the processing method are supplied in the form of a product stream (e.g. printed products supplied by a rotary printing machine) or they are taken from stocks where they are stored in discrete storage formations (e.g. reels, stacks) which storage formations are transformed into product streams for being supplied to the processing method. In an additional process step, the end products conveyed away from the processing method in form of product streams, can be collected in groups, e.g. in shipping units (e.g. packages). It is also possible to transform product streams of product parts coming out of processing steps into discrete storage formations (e.g. rolls, stacks) and, after an intermediate storage, to change the discrete storage formations into product streams again.
For different processing steps, substantially stationary automated processing stations are provided. Products are supplied to these stations in product streams and are conveyed away from them in product streams, whereby during processing, the items are continuously conveyed or are stationary. The product streams substantially consist of individual items (products) being conveyed in succession and being processed individually or in groups, whereby the items of one group are processed substantially in parallel.
Processing methods of the kind as described above are not only known from methods for processing products of printing machines, to which the examples given in brackets in the paragraphs above relate, but also e.g. from the assembly of printed circuit boards, from the packaging industry (e.g. cleaning, checking and filling of bottles) and from many different branches of industry in which piece-goods are processed.
Over the last decades, such processing of piece-goods has been developed to the aim of processing more items in less time. For this purpose, processing devices and conveying systems with increasing capacity have been developed. The application of transport means for conveying items individually and for processing them while being conveyed without the need for special guide means and without stopping the conveying movement has contributed considerably to this development. Such transport means are e.g. transport chains with equidistant grippers attached to them each for gripping one individual item and for holding the gripped items in a more or less defined position.
The development as described above has made it possible to drastically lower the processing costs per item, however, only under the condition that very large numbers of substantially identical items can be processed or that the items only receive a specific identity in as late a processing step as possible (e.g. by addressing).
It shows, however, that in the most various fields very high output of identical items burdens the market to such a degree that the prices must be lowered correspondingly which again has a negative effect on the economy of the processing. A way out of this negative spiral may consist in developing the processing methods such that various different end products can be produced by different processing of identical or different starting products, not only in substantially independent processes carried out after each other but in particular in predetermined sequences in which numbers of identical successive products are small in relation to the total output and show no regularity (e.g. production of the most various printed products in a sequence corresponding to a post route). This kind of development cogently leads to a larger number of necessary process steps and to increased requirements regarding flexibility (capacity to deal with fast temporal changes) of method and devices.
The kind of development as described above is also desirable for including more and more process steps in a highly automated processing method which steps were originally carried out on end products of automated processing methods by personnel (e.g. collecting different numbers of different printed products in groups, addressing the groups and directing them to the retailer according to the address).
Furthermore, there is a desire for such a development on the market side because the buyer of the processed items is rather prepared to buy at an adequate price if he or she receives a product corresponding more precisely to his or her wishes but still without delay.
Due to the described needs which all point in the same direction (differing end products in relatively fast succession) a corresponding development is observed in the field of piece-good processing. In other words attempts are made to design processing such that, with as little loss of capacity as possible, it allows differing processes for differing end products. This is mainly realized by conveying all of the products on the same path through processing stations in which they are processed or are not processed according to the end product they are to become.
It now shows that this development has reached its limit. On the one hand it becomes necessary to transfer more and more intermediate products from the substantially continuous process to intermediate storage in ever smaller groups. For this purpose these groups must be transformed into storage formations and then transformed back into product streams. Thus the method management for transferring these intermediately stored groups correctly back into the continuous method becomes very complex.
On the other hand the high flexibility demand of the named development causes faults to disturb the process to such a degree that provisions must be made to prevent faults by all means. Such provisions become very expensive.
An increased complexity is to be understood as a finer subdivision, e.g. in the sense of an extreme personalization of the processing of print products. The increase in complexity normally makes additional processing steps necessary. Thereby, it depends on how these additional processing steps are organized and carried out. The term `degree of freedom` is to be understood as the operative possibility to change the complexity in each process phase, i.e. selectively increasing or decreasing complexity at any point in time, even in the midst of a process. The subdivision of the print media into more and more different subjects (which leads to small editions and even mini-editions) being today more and more in demand and the drive toward more and more personalized products (totally opposed to any attempt to standardization in order to lower cost) together with retail prices that are rather falling than rising, urgently demands new processing methods showing higher flexibility.
Two examples for increasing the flexibility of per se known processing methods for products of printing machines are described in the publications EP-511159 (or U.S. Pat. No. 5,280,895) and DE-19524912 which both deal with the solution of the problem of creating a predetermined sequence of different products by means of controlled variation of the product part combinations.
Both methods according to the publications named above make use of known processing stations and known means for conveying product streams to the processing stations and away from them, especially conveying chains on which grippers are arranged for gripping, conveying and depositing one printed product each.
Both publications show clearly how complex the solutions of quite simple problems are and especially what extreme provisions must be made to prevent faults. Both publications thus show that for more complex problems the finding of new solutions is absolutely necessary.
It is therefore the object of the invention to create a method for processing piece-goods which method is to make it possible to go beyond the limitations of known such methods, i.e. even for a process of a high complexity (large number of process steps acting in different ways on items) the method is to have a considerably higher flexibility (ability to adapt to fast changes), without on the one hand expenditure becoming unacceptably high and without on the other hand further high expenditure for fault prevention.
Furthermore, it is the object of the invention to create a controlling method for controlling the processing method and an installation for carrying out the processing method.
These objects are achieved by the processing method, the controlling method and the installation as defined in the claims.